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Evolution Of Speech, The Physiology Of Speech, The Brain, Speech Impediments

Speech is defined as the ability to convey thoughts, ideas, or other information by means of articulating sound into meaningful words.

Many animals can make sounds and some can tailor these sounds to a given occasion. They may sound an alarm that a predator is in the area, warning others of their species that something has trespassed into their territory. Animals may make soothing sounds to let offspring know that their parent is present. These are only sounds of varying pitch or volume and do not constitute speech. Some animals, notably birds, can copy human speech to a minor extent and repeat words that they have been taught. This may be speech but limited control of vocal cords and a lack of flexible lips restricts the sounds that birds can imitate.

Some great apes such as the gorilla have been taught speech via sign language. They do not have the ability to form words because their larynx is not constructed to allow them to form certain sounds necessary for human speech. Some researchers have worked diligently to teach an ape to sign with its hands, to point to symbols in a board, or arrange marked blocks to form a thought, however incomplete. Thus, a gorilla can indicate that he or she wants an orange, wants to rest, or is cold but cannot communicate outside of these limited signs. A gorilla certainly cannot speak. One chimpanzee learned to sign more than 100 words and to put two or three symbols together to ask for something, but she was never able to place symbols together to express an idea.

Speech is unique to the human species. It is a means by which a people's history can be handed down from one generation to the next. It enables one person to convey knowledge to a roomful of other people. It can be used to amuse, to rouse, to anger, to express sadness, to communicate needs that arise between two or more humans.

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Science EncyclopediaScience & Philosophy: Spectroscopy to Stoma (pl. stomata)